1) Field of the Invention
Provided herein are compositions and methods for hair modification, and more particularly, compositions and methods that improve hair physical characteristics such as by increasing hair smoothness, strength, volume/thickness, and/or flexibility, including on a semi-permanent basis.
2) Background
There are a multitude of hair care products on the market that improve hair quality. Daily hair conditioners contain numerous ingredients that improve different aspects of hair quality including: moisturizers, reconstructors, acidifiers, detanglers, thermal protectors, glossers, oils, surfactants, lubricants, sequestrants, antistatic agents and preservatives. However, daily hair conditioners and even deep hair conditioners only provide for such improvement for a period of a few days. The benefit of most hair conditioners is lost after shampooing of the hair.
Long-term or semi-permanent hair smoothing products have been developed but have been wrought with health concerns. Several semi-permanent hair straightening products have been found to contain high levels of formaldehyde. Formaldehyde gas is released during the heating process used in the application of the product to the hair. Formaldehyde gas is a dangerous pollutant that can be severely irritating to the eyes, nose, throat, and long term exposure to formaldehyde has been associated with an increased risk of cancer. In April 2011, the U.S. Occupational Safety and Health Administration (OSHA) issued a hazard alert against the use of hair smoothing products containing formaldehyde. The Environmental Working Group investigated hair straighteners in 2011 for inclusion of formaldehyde, including formaldehyde dissolved in aqueous solutions, i.e., methylene glycol, which converts back to formaldehyde when water evaporates through the application of heat. The investigation concluded that many current products do not claim to include formaldehyde, but when tested, include significant levels of formaldehyde that exceed safety standards. See the Environmental Working Group report at www.ewg.org/hair-straighteners/our-report/hair-straighteners-that-hide-formaldehyde.
Accordingly, there is a need for compositions and methods that can be used to achieve semi-permanent smoothing, thickening and/or repair of hair that do not result in the formation of formaldehyde gas, or result in a negligible amount of formaldehyde gas formation.